KR20210089192A - Laminated core, manufacturing method of laminated core and rotating electric machine - Google Patents

Abstract

Provided is a rotary electric machine using a laminated core in which electrical steel sheets after punching are adhered with high adhesive strength. A plurality of electrical steel sheets laminated to each other and both surfaces covered with an insulating film, and an adhesive portion disposed between electrical steel sheets adjacent in a lamination direction to bond these electrical steel sheets to each other, and electrons adjacent to each other in a lamination direction All sets of steel sheets are adhered to each other by the bonding portion, the bonding portion is provided at a plurality of places between the electrical steel sheets, and the bonding portion contains either or both of an acrylic resin and an epoxy resin, and has an SP value of 7.8 to 10.7 ( A laminated core, which is a layer formed of an adhesive of ^1/2 cal/cm3).

Description

Laminated core, manufacturing method of laminated core and rotating electric machine

The present invention relates to a laminated core, a method for manufacturing the laminated core, and a rotating electric machine.

This application claims priority based on Japanese Patent Application No. 2018-235867 for which it applied to Japan on December 17, 2018, and uses the content here.

BACKGROUND ART Conventionally, as a core used in a rotating electric machine, a laminated core in which a plurality of electrical steel sheets are laminated on each other is known. A plurality of electrical steel sheets are joined by a method such as welding, bonding, or caulking.

Patent Document 1 discloses a laminated core in which electrical steel sheets after punching are adhered to each other with an epoxy resin, an acrylic resin, or the like.

Japanese Patent Laid-Open No. 2004-88970

However, in the conventional technique such as Patent Document 1, it is difficult to obtain sufficient adhesive strength between the electrical steel sheets after the punching process.

An object of the present invention is to provide a laminated core in which electrical steel sheets after punching are adhered with high adhesive strength, a method for manufacturing the same, and a rotary electric machine including the laminated core.

One embodiment of the present invention has the following aspects.

[1] a plurality of electrical steel sheets laminated on each other and both surfaces covered with an insulating film;

an adhesive portion disposed between the electrical steel sheets adjacent in the lamination direction and bonding these electrical steel sheets to each other;

all the sets of the electrical steel sheets adjacent in the lamination direction are adhered to each other by the plurality of bonding portions between the electrical steel sheets;

The bonding portion is provided at a plurality of places between the electrical steel sheets,

The laminated core, wherein the bonding portion is formed of an adhesive containing either or both of an acrylic resin and an epoxy resin, and having an SP value of 7.8 to 10.7 (cal/cm 3 ) ^1/2.

[2] The laminated core according to [1], wherein the adhesive is an epoxy resin adhesive containing an epoxy resin and a phenol novolac resin.

[3] The laminated core according to [2], wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an epoxy resin and 5 to 35 parts by mass of a phenol novolac resin.

[4] The laminate core according to [2], wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an epoxy resin, 5 to 35 parts by mass of a phenol novolac resin, and 5 to 50 parts by mass of an elastomer.

[5] The epoxy resin adhesive is 100 parts by mass of an epoxy resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 10 parts by mass of a solvent ^{having an SP value of 7.0 to 10.7 (cal/cm 3 ) 1/2.} phosphorus, the laminated core according to [2].

[6] The laminated core according to [2], wherein the epoxy resin adhesive further contains an acrylic resin.

[7] The laminate core according to [6], wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an acrylic modified epoxy resin obtained by graft polymerization of an acrylic resin and 5 to 35 parts by mass of a phenol novolac resin.

[8] In [6], wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an acrylic modified epoxy resin obtained by graft polymerization of an acrylic resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 50 parts by mass of an elastomer described laminated core.

[9] The laminate core according to [1], wherein the adhesive is an epoxy resin adhesive comprising an epoxy resin having a glass transition temperature of 120 to 180°C and an organophosphorus compound.

[10] The laminate core according to [1], wherein the adhesive is an epoxy resin adhesive comprising 100 parts by mass of an epoxy resin and 5 to 35 parts by mass of an organophosphorus compound.

[11] The adhesive is an epoxy resin adhesive comprising an epoxy resin, an epoxy resin curing agent, and an elastomer,

The laminated core according to [1], wherein the bonding portion has an average tensile modulus of elasticity at room temperature of 1500 to 5000 MPa and an average tensile modulus of elasticity at 150°C of 1000 to 3000 MPa.

[12] The laminated core according to any one of [1] to [11], which is an adhesive laminated core for a stator.

[13] A rotating electric machine comprising the laminated core according to any one of [1] to [12].

[14] The method for producing the laminated core according to [1],

A method for manufacturing a laminated core, wherein the adhesive is applied to the surface of the electrical steel sheet and then overlapped and pressed on a separate electrical steel sheet to repeat the operation of forming the bonding portion.

According to the present invention, it is possible to provide a laminated core in which electrical steel sheets after punching are adhered with high adhesive strength, a manufacturing method therefor, and a rotary electric machine including the laminated core.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the rotating electric machine provided with the adhesive laminated core for stators which concerns on one Embodiment of this invention.
Fig. 2 is a side view of a laminated core for the same stator.
Fig. 3 is a cross-sectional view taken along line AA of Fig. 2, and is a view showing an example of an arrangement pattern of the bonding portion of the adhesive laminated core for the stator.
It is a side view which shows the schematic structure of the manufacturing apparatus of the adhesive laminated core for stators.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, the adhesive laminated core for stators which concerns on one Embodiment of this invention, and the rotary electric machine provided with this adhesive laminated core for stators are demonstrated. In addition, in this embodiment, an electric motor, specifically an alternating current electric motor, more specifically a synchronous electric motor, and still more concretely a permanent magnet field type electric motor are mentioned as an example as a rotating electric machine and demonstrated. This type of electric motor is suitably employed, for example, in an electric vehicle or the like.

As shown in FIG. 1 , the rotating electric machine 10 includes a stator 20 , a rotor 30 , a case 50 , and a rotating shaft 60 . The stator 20 and the rotor 30 are accommodated in the case 50 . The stator 20 is fixed in the case 50 .

In the present embodiment, as the rotating electric machine 10 , an inner rotor type in which the rotor 30 is located radially inside the stator 20 is employed. However, as the rotary electric machine 10 , an outer rotor type in which the rotor 30 is located outside the stator 20 may be employed. In addition, in this embodiment, the rotary electric machine 10 is a 12-pole 18-slot three-phase AC motor. However, the number of poles, the number of slots, a constant, and the like can be appropriately changed.

The rotating electric machine 10 can rotate at a rotation speed of 1000 rpm by applying an excitation current of an effective value of 10 A and a frequency of 100 Hz to each phase, for example.

The stator 20 includes an adhesive laminated core for a stator (hereinafter referred to as a stator core) 21 and a winding (not shown).

The stator core 21 includes an annular core back portion 22 and a plurality of tooth portions 23 . Hereinafter, the central axis O direction of the stator core 21 (or the core back portion 22) is referred to as an axial direction, and the radial direction (orthogonal to the central axis O) of the stator core 21 (or the core back portion 22) direction) is referred to as a radial direction, and a circumferential direction (a direction revolving around the central axis O) of the stator core 21 (or the core back portion 22) is referred to as a circumferential direction.

The core back portion 22 is formed in an annular shape when the stator 20 is viewed in a plan view from the axial direction.

The plurality of teeth 23 protrude radially inward from the inner periphery of the core bag 22 (toward the central axis O of the core bag 22 along the radial direction). The plurality of tooth portions 23 are arranged at equal angular intervals in the circumferential direction. In the present embodiment, 18 tooth portions 23 are provided at an interval of 20 degrees at a central angle centering on the central axis O. The plurality of tooth portions 23 are formed to have an equal shape and to have an equal size. Accordingly, the plurality of tooth portions 23 have the same thickness dimension.

The winding is wound around the tooth portion 23 . The said winding may be centrally wound, and distribution winding may be sufficient as it.

The rotor 30 is arrange|positioned radially inside with respect to the stator 20 (stator core 21). The rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32 .

The rotor core 31 is formed in an annular shape (an annular shape) disposed coaxially with the stator 20 . The rotation shaft 60 is disposed in the rotor core 31 . The rotating shaft 60 is fixed to the rotor core 31 .

The plurality of permanent magnets 32 are fixed to the rotor core 31 . In this embodiment, two sets of permanent magnets 32 form one magnetic pole. A plurality of sets of permanent magnets 32 are arranged at equal angular intervals in the circumferential direction. In this embodiment, 12 sets (24 pieces in total) of permanent magnets 32 are provided at the center angle of 30 degree intervals centering on the central axis line O.

In the present embodiment, a buried magnet type motor is employed as the permanent magnet field type electric motor. The rotor core 31 is provided with a plurality of through holes 33 penetrating the rotor core 31 in the axial direction. The plurality of through holes 33 are provided corresponding to the arrangement of the plurality of permanent magnets 32 . Each permanent magnet 32 is fixed to the rotor core 31 while being disposed in the corresponding through hole 33 . The fixing of each permanent magnet 32 to the rotor core 31 can be realized, for example, by bonding the outer surface of the permanent magnet 32 and the inner surface of the through hole 33 with an adhesive. In addition, as a permanent magnet field type electric motor, you may employ|adopt a surface magnet type motor instead of a buried magnet type motor.

Both the stator core 21 and the rotor core 31 are laminated cores. For example, as shown in FIG. 2 , the stator core 21 is formed by laminating a plurality of electrical steel sheets 40 .

In addition, the lamination thickness (total length along the central axis O) of each of the stator core 21 and the rotor core 31 is set to 50.0 mm, for example. The outer diameter of the stator core 21 is set to, for example, 250.0 mm. The inner diameter of the stator core 21 is set to, for example, 165.0 mm. The outer diameter of the rotor core 31 is set to, for example, 163.0 mm. The inner diameter of the rotor core 31 is, for example, 30.0 mm. However, these values are examples, and the lamination thickness, outer diameter and inner diameter of the stator core 21, and the lamination thickness, outer diameter and inner diameter of the rotor core 31 are not limited to these values. Here, the inner diameter of the stator core 21 is based on the tip of the tooth portion 23 in the stator core 21 . That is, the inner diameter of the stator core 21 is the diameter of an imaginary circle inscribed at the tip of all the teeth 23 .

Each electrical steel sheet 40 forming the stator core 21 and the rotor core 31 is formed, for example, by punching an electrical steel sheet serving as a base material. As the electrical steel sheet 40, a well-known electrical steel sheet can be used. The chemical composition of the electrical steel sheet 40 is not particularly limited. In this embodiment, as the electrical steel sheet 40, a non-oriented electrical steel sheet is employed. As the non-oriented electrical steel sheet, for example, a non-oriented electrical steel sheet of JISC2552:2014 can be employed.

However, as the electrical steel sheet 40, it is also possible to employ a grain-oriented electrical steel sheet instead of the non-oriented electrical steel sheet. As the grain-oriented electrical steel sheet, for example, a grain-oriented electrical steel sheet according to JISC2553:2012 can be employed.

In order to improve the workability of the electrical steel sheet and the iron loss of the stator core, both surfaces of the electrical steel sheet 40 are coated with an insulating film. As a substance constituting the insulating film, for example, (1) an inorganic compound, (2) an organic resin, (3) a mixture of an inorganic compound and an organic resin, or the like can be employed. Examples of the inorganic compound include (1) a composite of dichromate and boric acid, and (2) a composite of phosphate and silica. As an organic resin, an epoxy resin, an acrylic resin, an acrylic styrene resin, a polyester resin, a silicone resin, a fluororesin, etc. are mentioned.

In order to ensure insulation performance between the electrical steel sheets 40 laminated to each other, the thickness of the insulating film (thickness per one side of the electrical steel sheet 40) is preferably 0.1 µm or more.

On the other hand, as the insulating film becomes thicker, the insulating effect is saturated. Further, as the insulating film becomes thicker, the space factor decreases and the performance as a stator core decreases. Therefore, the thickness of the insulating film is preferably within a range that can ensure insulating performance. The thickness of the insulating film (thickness per side of the electrical steel sheet 40) is preferably 0.1 µm or more and 5 µm or less, and more preferably 0.1 µm or more and 2 µm or less.

As the thickness of the electrical steel sheet 40 decreases, the effect of improving iron loss is gradually saturated. In addition, as the electrical steel sheet 40 becomes thinner, the manufacturing cost of the electrical steel sheet 40 increases. Therefore, in consideration of the improvement effect of iron loss and manufacturing cost, it is preferable that the thickness of the electrical steel sheet 40 be 0.10 mm or more.

On the other hand, when the electrical steel sheet 40 is too thick, the press punching operation of the electrical steel sheet 40 becomes difficult. Therefore, considering the press punching operation of the electrical steel sheet 40, it is preferable that the thickness of the electrical steel sheet 40 be 0.65 mm or less.

In addition, when the electrical steel sheet 40 is thickened, the iron loss is increased. Therefore, in consideration of the iron loss characteristics of the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.35 mm or less, more preferably 0.20 mm or 0.25 mm.

In consideration of the above points, the thickness of each electrical steel sheet 40 is, for example, 0.10 mm or more and 0.65 mm or less, preferably 0.10 mm or more and 0.35 mm or less, and more preferably 0.20 mm or 0.25 mm. In addition, the thickness of the electrical steel sheet 40 also includes the thickness of an insulating film.

As shown in FIG. 2 , in the stator core 21 , a plurality of bonding portions 41 for bonding the electrical steel sheets 40 to each other are provided between all sets of electrical steel sheets 40 adjacent in the lamination direction. . All sets of electrical steel sheets 40 adjacent in the lamination direction are bonded by a plurality of bonding portions 41 between the electrical steel sheets 40 . That is, the plurality of electrical steel sheets 40 forming the stator core 21 are laminated with the bonding portion 41 interposed therebetween. The electrical steel sheets 40 adjacent in the lamination direction are not fixed by other means (for example, caulking or the like).

The bonding portion 41 bonds the electrical steel sheets 40 adjacent to each other in the lamination direction. The bonding portion 41 is a portion formed of an adhesive (hereinafter, adhesive (X)) containing either or both of an acrylic resin and an epoxy resin, and having an SP value of 7.8 to 10.7 (cal/cm 3 ) ^1/2. That is, the adhesive part 41 is the adhesive agent X hardened|cured without being parted.

In addition, the SP value means the solubility parameter defined by Hildebrand. The SP value of the adhesive (X) is measured from the solubility of a cured product obtained by curing the adhesive (X) in various solvents for which the SP value is known. More specifically, it is measured by the method described in the Examples.

In this specification, "to" which shows a numerical range means that the numerical value described before and after that is included as a lower limit and an upper limit.

When a laminated core is obtained by laminating a plurality of electrical steel sheets after punching by bonding with an adhesive usually used, it is difficult to obtain sufficient adhesive strength between electrical steel sheets compared to a case where punching is not performed. This is considered to be because the punching oil used at the time of the punching process remains on the laminated surface of the electrical steel sheet and intervenes between the laminated surface of the electrical steel sheet at the time of lamination and the adhesive, thereby inhibiting adhesion.

It is considered that the SP value of the punching oil is close to cyclohexane (SP value: 8.2 (cal/cm 3 ) ^1/2 ) or toluene (SP value: 8.9 (cal/cm 3 ) ^1/2 ). In the present invention, since the SP value of the adhesive (X) ^{is controlled in the range of 7.8 to 10.7 (cal/cm 3 ) 1/2} , the compatibility with the punching oil is excellent. Accordingly, the adhesive (X) exhibits excellent oil-level adhesiveness in lamination of the electrical steel sheets after the punching process, and the electrical steel sheets are adhered to each other with high adhesive strength. Therefore, the stator core 21 with high mechanical strength and low noise and low vibration is obtained.

In addition, if the SP value of the adhesive (X) is in the range of 7.8 to 10.7 (cal/cm 3 ) ^1/2 , even if there is a difference between the SP value of the adhesive (X) and the SP value of the punching oil, it is a laminated core with low noise and low vibration. do.

The SP value of the adhesive (X) is preferably from 8.0 to 10.0 (cal/cm 3 ) ^1/2 , and more preferably from 8.2 to 8.9 (cal/cm 3 ) ^{1/2 from the viewpoint of improving the oil surface adhesiveness.}

The SP value of the adhesive (X) is more preferably set in an optimal range according to the type of punching oil. For example, when the punching oil is mineral oil, the SP value of the adhesive (X) is more preferably ^{8.2 to 8.9 (cal/cm 3 ) 1/2.} When the punching oil is isoparaffin, the SP value of the adhesive (X) is more preferably ^{7.8 to 8.5 (cal/cm 3 ) 1/2.} When the punching oil is toluene, the SP value of the adhesive (X) is more preferably ^{8.5 to 9.3 (cal/cm 3 ) 1/2.}

As a method of adjusting the SP value of adhesive agent (X), in the case of an epoxy resin type adhesive agent, the method of graft-polymerizing an acrylic resin to an epoxy resin can be illustrated, for example. By graft-polymerizing an acrylic resin with an epoxy resin, there exists a tendency for SP value to fall. Moreover, in this case, there exists a tendency for SP value to fall, so that the polymerization degree of an acrylic resin is high. Moreover, SP value can also be adjusted by mix|blending an additive with adhesive agent (X). For example, when the adhesive (X) is an epoxy resin-based adhesive, an ^{additive having a smaller SP value than an epoxy resin (SP value: about 10.9 (cal/cm 3 ) 1/2} ), that is, a low polarity, is added to the adhesive (X) The SP value of can be reduced.

As an additive which adjusts the SP value of adhesive agent (X), what is necessary is just what does not affect the adhesiveness of adhesive agent (X), or the performance of a rotating electric machine. For example, n-pentane (SP value: 7.0 (cal/cm 3 ) ^1/2 ), n-hexane (SP value: 7.3 (cal/cm 3 ) ^1/2 ), diethyl ether (SP value: 7.4 (cal) /cm3) ^1/2 ), n-octane (SP value: 7.6(cal/cm3) ^1/2 ), vinyl chloride (SP value: 7.8(cal/cm3) ^1/2 ), cyclohexane, isobutyl acetate ( SP value: 8.3(cal/cm3) ^1/2 ), isopropyl acetate (SP value: 8.4(cal/cm3) ^1/2 ), butyl acetate (SP value: 8.5(cal/cm3) ^1/2 ), carbon tetrachloride (SP value: 8.6(cal/cm3) ^1/2 ), methylpropyl ketone (SP value: 8.7(cal/cm3) ^1/2 ), xylene (SP value: 8.8(cal/cm3) ^1/2 ), toluene , ethyl acetate (SP value: 9.1(cal/cm3) ^1/2 ), benzene (SP value: 9.2(cal/cm3) ^1/2 ), methyl ethyl ketone (SP value: 9.3(cal/cm3) ^{1/2 )} ), methylene chloride (SP value: 9.7(cal/cm3) ^1/2 ), acetone (SP value: 9.9(cal/cm3) ^1/2 ), carbon disulfide (SP value: 10.0(cal/cm3) ^{1/2 )} ), acetic acid (10.1 (cal/cm 3 ) ^1/2 ) and n-hexanol (SP value: 10.7 (cal/cm 3 ) ^1/2 ) SP value selected from the group consisting of 7.0 to 10.7 (cal/cm 3 ) At least 1 type of solvent among ^{1/2 can be illustrated.} Moreover, the SP value of adhesive agent (X) can also be made small by mix|blending elastomers, such as synthetic rubber with a small SP value mentioned later. One type may be sufficient as the additive mix|blended with adhesive agent (X), and 2 or more types may be sufficient as it.

As the adhesive (X), an epoxy resin-based adhesive containing an epoxy resin and an acrylic resin-based adhesive containing an acrylic resin can be exemplified. In addition, the acrylic resin adhesive does not contain an epoxy resin. From the viewpoint of excellent heat resistance and adhesiveness, an epoxy resin-based adhesive is preferable.

The epoxy resin adhesive contains an epoxy resin and a curing agent. In addition to the epoxy resin and the hardening|curing agent, the epoxy resin-type adhesive agent which further contains an acrylic resin is preferable at the point excellent in heat resistance, quick curing property, and oil surface adhesiveness. An epoxy resin adhesive containing an acrylic modified epoxy resin obtained by graft polymerization of an acrylic resin to an epoxy resin may be used.

It does not specifically limit as an epoxy resin, For example, a bisphenol A-type epoxy resin, a bisphenol F-type epoxy resin, a bisphenol AD-type epoxy resin, a glycidylamine-type epoxy resin, and an alicyclic epoxy resin can be illustrated. Especially, a bisphenol F-type epoxy resin is preferable at the point which is low in viscosity and is excellent in workability|operativity. The number of epoxy resins contained in an epoxy resin adhesive may be one, and 2 or more types may be sufficient as them.

80-150 degreeC is preferable, as for the glass transition temperature (Tg) of an epoxy resin, 100-150 degreeC is more preferable, 120-150 degreeC is still more preferable. It is excellent in heat resistance as Tg of an epoxy resin is more than the lower limit of the said range, and a stator core with high mechanical strength is easy to be obtained. When Tg of an epoxy resin is below the upper limit of the said range, adhesiveness with a steel plate is easy to be acquired.

In addition, Tg of an epoxy resin is the midpoint glass transition temperature measured by the differential scanning calorimetry (DSC) method according to JISK7121-1987.

1200-20000 are preferable, as for the number average molecular weight (Mn) of an epoxy resin, 2000-18000 are more preferable, and 2,500-16000 are still more preferable. It is easy to raise adhesive strength as Mn of an epoxy resin is more than the lower limit of the said range. It is easy to suppress that an epoxy resin adhesive becomes high viscosity as Mn of an epoxy resin is below the upper limit of the said range.

In addition, Mn of an epoxy resin can be measured by size-exclusion chromatography (SEC: Size-Exclusion Chromatography) described in JISK7252-1:2008 using polystyrene as a standard material.

It does not specifically limit as a hardening|curing agent, A commonly used epoxy resin hardening|curing agent can be used. A low temperature or room temperature hardening type may be sufficient as a hardening|curing agent, and a heat hardening type may be sufficient as it. As a specific example of a hardening|curing agent, an aliphatic polyamine, an aromatic polyamine, an acid anhydride, a phenol novolak resin, an organophosphorus compound, and dicyandiamide (DICY) can be illustrated, for example. The number of hardening|curing agents contained in an epoxy resin adhesive may be one, and 2 or more types may be sufficient as it.

Examples of the aliphatic polyamine include triethylenetetramine, diethylenetriamine (DTA) and diethylaminopropylamine (DEAPA).

Examples of the aromatic polyamine include diaminodiphenylmethane (DDM), metaphenylenediamine (MPDA), and diaminodiphenylsulfone (DDS).

As an acid anhydride, phthalic anhydride, hexahydrophthalic anhydride, and 4-methylhexahydrophthalic anhydride can be illustrated, for example.

A phenol novolak resin is a novolak-type phenol resin obtained by carrying out the condensation reaction of phenols (phenol etc.) and aldehydes (formaldehyde etc.) using an acid catalyst.

The organophosphorus compound is not particularly limited, and for example, hexamethyl phosphate triamide, phosphate tri (dichloropropyl), phosphate tri (chloropropyl), phosphite triphenyl, trimethyl phosphate, phenyl phosphonic acid, triphenyl phosphine, tri-n-butylphosphine and diphenylphosphine can be exemplified.

As the curing agent, from the viewpoint of excellent heat resistance, a heat curing type curing agent is preferable, more preferably a phenol novolak resin or an aromatic polyamine, and a phenol novolak resin is particularly preferable from the viewpoint of easily obtaining a stator core with high mechanical strength. . When using 2 or more types of epoxy resin hardening|curing agents, the aspect which mixes an aromatic polyamine with a phenol novolak resin as a main component is mentioned, for example.

Content of the hardening|curing agent in an epoxy resin adhesive can be suitably set according to the kind of hardening|curing agent, For example, when using a phenol novolak resin, 5-35 mass parts is preferable with respect to 100 mass parts of epoxy resins. When using an organophosphorus compound as a hardening|curing agent, as for content of an organophosphorus compound, 5-35 mass parts is preferable with respect to 100 mass parts of epoxy resins.

You may mix|blend a hardening accelerator with an epoxy resin adhesive. As a hardening accelerator, a tertiary amine, a secondary amine, and imidazole can be illustrated, for example. The number of hardening accelerators contained in an epoxy resin adhesive may be one, and 2 or more types may be sufficient as it.

It does not specifically limit as an acrylic resin. As a monomer used for an acrylic resin, For example, unsaturated carboxylic acids, such as acrylic acid and methacrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate (meth)acrylates such as acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and hydroxypropyl (meth)acrylate are exemplified. can do. In addition, (meth)acrylate means an acrylate or a methacrylate. One type may be sufficient as the acrylic resin contained in adhesive agent (X), and 2 or more types may be sufficient as it.

When using an acrylic resin for an adhesive agent, in the adhesive agent before hardening, you may contain as a monomer which forms an acrylic resin.

5000-100000 are preferable, as for the number average molecular weight (Mn) of an acrylic resin, 6000-80000 are more preferable, 7000-60000 are still more preferable. It is easy to raise adhesive strength as Mn of an acrylic resin is more than the lower limit of the said range. It is easy to suppress that adhesive agent (X) becomes high viscosity as Mn of an acrylic resin is below the upper limit of the said range.

In addition, Mn of an acrylic resin can be measured by the method similar to Mn of an epoxy resin.

When an epoxy resin adhesive contains an acrylic resin, content in particular of an acrylic resin is not restrict|limited, For example, it can be 20-80 mass % with respect to the total amount of an epoxy resin and an acrylic resin. Content of the acrylic resin in the acrylic modified epoxy resin by which the acrylic resin was graft-polymerized is also the same, for example, can be 20-80 mass % with respect to the total mass of the acrylic modified epoxy resin.

The epoxy resin adhesive may also contain an elastomer. By blending the elastomer, the average tensile modulus of elasticity of the bonding portion 41 can be controlled within a specific range, contributing to the improvement of the viscosity and flow properties.

Examples of the elastomer include natural rubber and synthetic rubber, and synthetic rubber is preferable. One type may be sufficient as the elastomer contained in an epoxy resin adhesive agent, and 2 or more types may be sufficient as it.

Examples of the synthetic rubber include polybutadiene-based synthetic rubber, nitrile-based synthetic rubber, and chloroprene-based synthetic rubber.

Examples of the polybutadiene-based synthetic rubber include isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), polyisobutylene (butyl rubber, IIR), and ethylene propylene diene rubber (EPDM). can Examples of the nitrile-based synthetic rubber include acrylonitrile-butadiene rubber (NBR) and acrylic rubber (ACM). Examples of the chloroprene-based synthetic rubber include chloroprene rubber (CR).

EPDM(SP value: 7.9~8.0(cal/cm3) ^1/2 ), SBR(SP value: 8.1~8.7(cal/cm3) ^1/2 ), BR(SP value: 8.1~8.6(cal/cm3) ^{1 /2} ) and NBR (SP value: 8.7 to 10.5 (cal/cm 3 ) ^1/2 ), an elastomer having a smaller SP value than an epoxy resin can also be used for the purpose of adjusting the SP value of the adhesive (X). By using such an elastomer, it is possible to control the average tensile modulus while improving the oil surface adhesion. Moreover, by mix|blending with the adhesive agent (X) the elastomer whose SP value is lower than an epoxy resin, it can be set as the laminated core of especially low vibration and low noise. Although the mechanism for achieving low vibration and low noise by mixing the elastomer is not necessarily clear, it is considered that the elastomer with a low SP value increases the adhesive strength and vibration absorption performance between the electrical steel sheets.

Preferred examples of the epoxy resin adhesive include an adhesive containing an epoxy resin and a phenol novolac resin, an adhesive containing an epoxy resin, a phenol novolak resin, and an acrylic resin, an adhesive containing an epoxy resin and an organophosphorus compound having a Tg of 120 to 180°C , an adhesive containing an epoxy resin, an epoxy resin curing agent, and an elastomer can be exemplified.

As more preferable epoxy resin adhesives, adhesives (X1) to (X6) having the following compositions can be exemplified.

Adhesive (X1): An adhesive comprising 100 parts by mass of an epoxy resin and 5 to 35 parts by mass of a phenol novolac resin.

Adhesive (X2): The adhesive agent which consists of 100 mass parts of epoxy resins and 5-35 mass parts of organophosphorus compounds.

Adhesive (X3): An adhesive comprising 100 parts by mass of an epoxy resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 50 parts by mass of an elastomer.

Adhesive (X4): An adhesive comprising 100 parts by mass of an acrylic modified epoxy resin obtained by graft polymerization of an acrylic resin and 5 to 35 parts by mass of a phenol novolac resin.

Adhesive (X5): An adhesive comprising 100 parts by mass of an acrylic modified epoxy resin obtained by graft polymerization of an acrylic resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 50 parts by mass of an elastomer.

Adhesive (X6): An adhesive comprising 100 parts by mass of an epoxy resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 10 parts by mass of a solvent ^{having an SP value of 7.0 to 10.7 (cal/cm 3 ) 1/2.}

In these adhesives (X1) to (X6), each preferable embodiment of an epoxy resin, an organophosphorus compound, and an elastomer can be appropriately combined.

When the adhesive part 41 is formed with an epoxy resin-based adhesive comprising an epoxy resin having a Tg of 120 to 180° C., an epoxy resin curing agent, and an elastomer, the adhesive part 41 has an average tensile modulus at room temperature of 1500 to 5000 MPa, It is preferable that the average tensile elasticity modulus in 150 degreeC is 1000-3000 MPa. In this case, the bonding portion 41 formed of an epoxy resin adhesive comprising 100 parts by mass of an epoxy resin having a Tg of 120 to 180° C., 5 to 35 parts by mass of an epoxy resin curing agent, and 5 to 50 parts by mass of an elastomer is more preferable.

1500-5000 Mpa is preferable and, as for the average tensile elasticity modulus in normal temperature of the bonding part 41, 1500-4000 Mpa is more preferable. When the average tensile modulus at room temperature is equal to or more than the lower limit of the above range, the core loss property of the laminated core is excellent. When the average tensile modulus at room temperature is equal to or less than the upper limit of the above range, the bonding strength of the laminated core is excellent.

In addition, the average tensile modulus in normal temperature is the value measured at 25 degreeC by the resonance method by producing the sample for a measurement. Specifically, the sample is obtained by bonding the two electrical steel sheets 40 with an adhesive to be measured, and curing them to form the bonding portion 41 . The average tensile modulus of this sample is measured by a resonance method based on JIS R1602:1995. Thereafter, the average tensile modulus of elasticity of the bonding portion 41 alone is obtained by dividing the influence component of the electrical steel sheet 40 itself from the average tensile modulus (measured value) of the sample by calculation.

Since the tensile modulus of elasticity obtained from the sample in this way becomes equal to the average value of the entire laminated core, it is regarded as the average tensile modulus with this numerical value. The composition is set so that the average tensile modulus of elasticity hardly changes at a lamination position along the lamination direction or a circumferential position around the central axis of the lamination core. Therefore, the average tensile elastic modulus E may have a numerical value obtained by measuring the cured bonding portion 41 at the upper end position of the laminated core, and may be taken as the value.

Moreover, 1000-3000 MPa is preferable, as for the average tensile elasticity modulus in 150 degreeC of the bonding part 41, 1000-2800 MPa is more preferable, and its 1000-2500 are still more preferable. When the average tensile modulus at 150° C. is equal to or greater than the lower limit of the above range, the bonding strength of the laminated core is excellent. When the average tensile modulus at 150° C. is equal to or less than the upper limit of the above range, the core loss property of the laminated core is excellent.

In addition, the average tensile modulus in 150 degreeC is the value measured at 150 degreeC by the resonance method. The average tensile modulus at 150°C is measured by the same method as the average tensile modulus at room temperature except for the measurement temperature.

The thickness of the bonding portion 41 is preferably 1 µm or more in order to stably obtain sufficient bonding strength.

On the other hand, when the thickness of the adhesive part 41 exceeds 100 μm, the adhesive force is saturated. In addition, as the bonding portion 41 becomes thicker, the space factor decreases, and magnetic properties such as iron loss of the stator core decrease. Therefore, it is preferable to set it as 1 micrometer or more and 100 micrometers or less, and, as for the thickness of the bonding part 41, it is more preferable to set it as 1 micrometer or more and 10 micrometers or less.

In addition, in the above, the thickness of the adhesive part 41 means the average thickness of the adhesive part 41. As shown in FIG.

As for the average thickness of the bonding part 41, it is more preferable to set it as 1.0 micrometer or more and 3.0 micrometers or less. If the average thickness of the adhesive portion 41 is less than 1.0 μm, sufficient adhesive force cannot be ensured as described above. Therefore, the lower limit of the average thickness of the bonding portion 41 is 1.0 µm, more preferably 1.2 µm. Conversely, if the average thickness of the bonding portion 41 exceeds 3.0 μm and becomes thicker, problems such as a significant increase in the amount of deformation of the electrical steel sheet 40 due to shrinkage during thermal curing occur. Therefore, the upper limit of the average thickness of the bonding portion 41 is 3.0 µm, more preferably 2.6 µm.

The average thickness of the bonding portion 41 is an average value of the entire laminated core. The average thickness of the bonding portion 41 hardly changes at a lamination position along its lamination direction or a circumferential position around the central axis of the lamination core. Therefore, the average thickness of the bonding part 41 can be set as the value with the average value of the numerical values measured at 10 or more locations in the circumferential direction in the upper end position of the laminated core.

In addition, the average thickness of the adhesive part 41 can be adjusted by changing the application amount of an adhesive agent, for example. In addition, the average tensile modulus of elasticity of the bonding part 41 can be adjusted by changing the heating conditions and pressure conditions applied at the time of bonding, and the kind of hardening|curing agent, etc., for example.

The bonding portions 41 are provided at a plurality of locations between the electrical steel sheets 40 adjacent to each other in the lamination direction. That is, as shown in FIG. 3 , an adhesive region 42 and a non-bonding region 43 are formed on the surface (first surface) facing the lamination direction of the electrical steel sheet 40 . The bonding region 42 is a region in which the adhesive part 41 is provided among the first surfaces of the electrical steel sheet 40 , that is, an area in which the adhesive X cured without being divided among the first surfaces of the electrical steel sheet 40 is provided. to be. The non-adhesive region 43 is a region in which the adhesive portion 41 is not provided among the first surface of the electrical steel sheet 40 , that is, the adhesive (X) that is cured without being divided among the first surface of the electrical steel sheet 40 . This is an area that is not provided. In the stator core 21 , between the electromagnetic steel sheets 40 adjacent in the lamination direction, the bonding portion 41 is partially provided between the core back portions 22 and also partially between the teeth portions 23 . It is preferable to be provided with

The bonding portions 41 are typically arranged to be dispersed in a plurality of locations between the electrical steel sheets 40 adjacent to each other in the lamination direction.

3 is an example of an arrangement pattern of the bonding portion 41 . In this example, the bonding part 41 is formed in the shape of a plurality of points forming a circle. More specifically, in the core back portion 22, a plurality of bonding portions 41 are formed in a dotted shape with an average diameter of 12 mm at equal angular intervals in the circumferential direction thereof. In each tooth portion 23, a plurality of bonding portions 41 are formed in a dotted shape with an average diameter of 8 mm along the radial direction.

The average diameter shown here is an example. It is preferable that the average diameter of the point-shaped bonding part 41 in the core back part 22 shall be 2-20 mm. It is preferable that the average diameter of the point-shaped bonding part 41 in each tooth part 23 shall be 2-15 mm. In addition, the formation pattern of FIG. 3 is an example, and the number, shape, and arrangement|positioning of the bonding parts 41 provided between the electrical steel sheets 40 comrades can be changed suitably as needed.

The average diameter is calculated|required by measuring the diameter of the adhesive bond trace of the bonding part 41 which peeled the electrical steel sheets 40 comrades by regularity. When the planar shape of the adhesive trace is not a perfect circle, the diameter is the diameter of the circumscribed circle (perfect circle) of the adhesive trace in plan view.

(Method for manufacturing laminated core)

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, the manufacturing method of the adhesive laminated core for stators which concerns on one Embodiment of this invention is demonstrated.

The stator core 21 can be manufactured by repeating the operation of applying the adhesive X to a plurality of places on the surface of the electrical steel sheet 40, then overlapping and pressing on a separate electrical steel sheet to form the adhesive portion 41. have.

Below, the method of manufacturing the stator core 21 using the manufacturing apparatus 100 shown in FIG. 4 is demonstrated.

First, the manufacturing apparatus 100 is demonstrated. In the manufacturing apparatus 100, the electromagnetic steel sheet P is sent out from the coil C (hoops) in the direction of the arrow F, punching is performed a plurality of times with a die arranged on each stage to form little by little into the shape of the electromagnetic steel sheet 40. , the adhesive (X) is applied to a predetermined position on the lower surface of the electrical steel sheet 40 after the second sheet, and the punched electrical steel sheet 40 is sequentially laminated and pressed.

As shown in FIG. 4 , the manufacturing apparatus 100 has a first stage punching station 110 at a position closest to the coil C, and on the downstream side along the conveyance direction of the electrical steel sheet P from the punching station 110 . A second-stage punching station 120 disposed adjacent to each other, and an adhesive application station 130 disposed adjacent to the punching station 120 on the downstream side are provided.

The punching station 110 includes a female mold 111 disposed below the electrical steel sheet P, and a male mold 112 disposed above the electrical steel sheet P.

The punching station 120 includes a female mold 121 disposed below the electrical steel sheet P, and a male mold 122 disposed above the electrical steel sheet P.

The adhesive application station 130 includes an applicator 131 having a plurality of injectors arranged according to the arrangement pattern of the adhesive portion 41 described above.

The manufacturing apparatus 100 is further equipped with the lamination|stacking station 140 at a position downstream of the adhesive agent application station 130. As shown in FIG. The lamination station 140 includes a heating device 141 , an outer peripheral punching female mold 142 , a heat insulating member 143 , an outer peripheral punching male mold 144 , and a spring 145 .

The heating device 141 , the outer peripheral punching female die 142 , and the heat insulating member 143 are disposed below the electrical steel sheet P .

The outer peripheral punching male die 144 and the spring 145 are disposed above the electrical steel sheet P.

<Punching process>

In the manufacturing apparatus 100 having the above configuration, first, the electromagnetic steel sheet P is sequentially sent out from the coil C in the direction of the arrow F in FIG. 4 . Then, the electrical steel sheet P is first subjected to punching by the punching station 110 . Subsequently, punching processing is performed on this electrical steel sheet P by the punching station 120 . By these punching processes, the shape of the electrical steel sheet 40 having the core back portion 22 and the plurality of tooth portions 23 shown in FIG. 3 is obtained in the electrical steel sheet P. However, since punching is not completely punched at this point, it progresses to the next process along the arrow F direction.

<Applying process>

In the adhesive application station 130 in the next step, the adhesive X is supplied from each of the injectors of the applicator 131 , and the adhesive X is applied to a plurality of points on the lower surface of the electrical steel plate 40 in the form of dots. .

<Lamination process>

Then, the electrical steel sheet P is sent out to the lamination station 140, punched by the outer peripheral punching male mold 144, and laminated with high precision. For example, by forming cut-outs at a plurality of locations on the outer peripheral end of the core back portion and pressing a scale from the side against the cut-outs, it is possible to prevent misalignment of each electrical steel sheet 40, and to stack with higher precision. can During lamination, the electrical steel sheet 40 is subjected to a constant pressing force by the spring 145 . When the adhesive (X) is of a heat-curing type, it is heated, for example, at 150 to 160°C by the heating device 141 to accelerate curing.

By sequentially repeating the punching process, the coating process, and the lamination process as described above, a predetermined number of the electrical steel sheets 40 can be laminated via the bonding portion 41 .

By each of the above steps, the stator core 21 is completed.

In addition, the technical scope of this invention is not limited to the said embodiment, In the range which does not deviate from the meaning of this invention, it is possible to add various changes.

The shape of the stator core is not limited to the form shown in the above embodiment. Specifically, the dimensions of the outer and inner diameters of the stator core, the stacking thickness, the number of slots, the ratio of dimensions in the circumferential and radial directions of the teeth, and the ratio of dimensions in the radial direction of the teeth and the core back, etc. depend on the characteristics of the desired rotating electric machine. It can be arbitrarily designed according to

In the rotor in the above embodiment, two sets of permanent magnets 32 form one magnetic pole, but the present invention is not limited thereto. For example, one permanent magnet 32 may form one magnetic pole, and three or more permanent magnets 32 may form one magnetic pole.

In the above embodiment, as the rotating electric machine, a permanent magnet field type electric motor has been described as an example. However, the structure of the rotating electric machine is not limited to this as illustrated below, and furthermore, various known structures not illustrated below are not limited to the structure of the rotating electric machine. Structures can also be employed.

In the above embodiment, a permanent magnet field type electric motor was described as an example of the rotating electric machine, but the present invention is not limited thereto. For example, the rotating electric machine may be a reluctance type electric motor or an electromagnet field type electric motor (winding field type electric motor).

In the above embodiment, as the AC motor, the synchronous motor was described as an example, but the present invention is not limited thereto. For example, the rotating electric machine may be an induction motor.

In the said embodiment, although an AC electric motor was mentioned and demonstrated as an example as an electric motor, this invention is not limited to this. For example, the rotating electric machine may be a direct current electric motor.

In the above embodiment, an electric motor was described as an example of the rotating electric machine, but the present invention is not limited thereto. For example, the rotating electric machine may be a generator.

Although the case where the laminated core which concerns on this invention is applied to a stator core was illustrated in the said embodiment, it is also possible to apply to a rotor core.

It is also possible to employ the laminated core in a transformer instead of a rotating electric machine. In this case, instead of employing a grain-oriented electrical steel sheet as the electrical steel sheet, it is preferable to employ a grain-oriented electrical steel sheet.

In addition, in the range which does not deviate from the meaning of this invention, it is possible to substitute the component in the said embodiment with a well-known component suitably, and you may combine the above-mentioned modified example suitably.

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by the following description.

[SP value]

The SP value of the adhesive was measured by the following method. An adhesive was applied to the surface of the non-oriented electrical steel sheet and cured by heating at 120°C. With respect to the obtained cured product, various solvents having known SP values shown in Table 1 were rubbed, and when the cured product was peeled off by dissolving the solvent in the cured product, the SP value of the solvent was taken as the SP value of the adhesive.

In the measurement of the SP value of the adhesive, each solvent shown in Table 1 and a mixed solvent having an SP value adjusted by appropriately mixing two of them are prepared, and the SP value is measured at 0.1 intervals in the range of 7.0 to 11.4. made it possible When hardened|cured material was melt|dissolved in several solvent and peeled, the SP value of the solvent from which hardened|cured material peels most easily among those solvents was made into the SP value of an adhesive agent.

[Tensile Modulus]

The average tensile modulus at room temperature was measured at 25°C by the resonance method. The average tensile elastic modulus in 150 degreeC was measured by the method similar to the average tensile elastic modulus in normal temperature except the measurement temperature being 150 degreeC.

[Example 1]

An adhesive (X-1) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 20 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (X-1) was 8.1 (cal/cm 3 ) ^1/2 .

The shear tensile test piece mentioned later was produced using the adhesive agent (X-1), and oil surface adhesiveness was evaluated. In addition, vibration and noise of the laminated core produced using the adhesive (X-1) were also evaluated.

[Example 2]

An adhesive (X-2) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 25 parts by mass of hexamethyl phosphate triamide as an organophosphorus compound. . The SP value of the obtained adhesive (X-2) was 8.5 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-2) was used instead of the adhesive (X-1).

[Example 3]

100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 20 parts by mass of phenol novolac resin as an epoxy resin curing agent, and 5 parts by mass of EPDM as an elastomer. X-3) was prepared. The SP value of the obtained adhesive (X-3) was 8.2 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-3) was used instead of the adhesive (X-1). In addition, the average tensile elastic modulus at room temperature of the bonding part was 3000 MPa, and the average tensile elastic modulus at 150 degreeC was 2000 MPa.

[Example 4]

60 parts by mass of methyl methacrylate and 40 parts by mass of cyclohexyl methacrylate were mixed to prepare an adhesive (X-4). The SP value of the obtained adhesive (X-4) was 10.2 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-4) was used instead of the adhesive (X-1).

[Example 5]

100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 20 parts by mass of a phenol novolac resin as an epoxy resin curing agent, and 5 parts by mass of cyclohexane as a solvent. (X-5) was prepared. The SP value of the obtained adhesive (X-5) was 8.0 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-5) was used instead of the adhesive (X-1).

[Example 6]

An adhesive (X-6) was prepared by mixing 100 parts by mass of an acrylic modified epoxy resin in which an acrylic resin was graft-polymerized (content of acrylic resin: 30% by mass) and 20 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (X-6) was 7.8 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-6) was used instead of the adhesive (X-1).

[Example 7]

100 parts by mass of an acrylic-modified epoxy resin (acrylic resin content: 30% by mass) obtained by graft polymerization of an acrylic resin, 10 parts by mass of a phenol novolac resin as an epoxy resin curing agent, and 20 parts by mass of butadiene rubber as an elastomer. X-7) was prepared. The SP value of the obtained adhesive (X-7) was 9.1 (cal/cm 3 ) ^1/2 .

Oil surface adhesion, vibration and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-7) was used instead of the adhesive (X-1).

[Example 8]

An adhesive (X-8) was prepared by mixing 100 parts by mass of a bisphenol A epoxy resin (Tg: 110° C.) obtained by polymerizing bisphenol A and epichlorohydrin and 20 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (X-8) was 8.0 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-8) was used instead of the adhesive (X-1).

[Example 9]

An adhesive (X-9) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 10 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (X-9) was 9.5 (cal/cm 3 ) ^1/2 .

Oil surface adhesion, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-9) was used instead of the adhesive (X-1).

[Example 10]

An adhesive (X-10) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 30 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (X-10) was 7.9 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-10) was used instead of the adhesive (X-1).

[Example 11]

An adhesive (X-11) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 10 parts by mass of hexamethyl phosphate triamide as an organophosphorus compound. . The SP value of the obtained adhesive (X-11) was 9.9 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-11) was used instead of the adhesive (X-1).

[Example 12]

100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 20 parts by mass of phenol novolac resin as an epoxy resin curing agent, and 40 parts by mass of EPDM as an elastomer. X-12) was prepared. The SP value of the obtained adhesive (X-12) was 7.9 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration and noise were evaluated in the same manner as in Example 1 except that the adhesive (X-12) was used instead of the adhesive (X-1). In addition, the average tensile elastic modulus at room temperature of the bonding part was 1600 MPa, and the average tensile elastic modulus at 150 degreeC was 1100 MPa.

[Example 13]

100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 20 parts by mass of a phenol novolac resin as an epoxy resin curing agent, and 30 parts by mass of cyclohexane as a solvent. (X-13) was prepared. The SP value of the obtained adhesive (X-13) was 7.8 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-13) was used instead of the adhesive (X-1).

[Example 14]

An adhesive (X-14) was prepared by mixing 100 parts by mass of an acrylic modified epoxy resin in which an acrylic resin was graft-polymerized (content of acrylic resin: 60% by mass) and 10 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (X-14) was 7.9 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1 except that the adhesive (X-14) was used instead of the adhesive (X-1).

[Example 15]

100 parts by mass of a glycidylamine-type epoxy resin (Tg: 160°C) and 25 parts by mass of hexamethyl phosphate triamide as an organophosphorus compound were mixed to prepare an adhesive (X-15). The SP value of the obtained adhesive (X-15) was 8.4 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (X-15) was used instead of the adhesive (X-1).

[Comparative Example 1]

An adhesive (Y-1) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 3 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (Y-1) was 10.8 (cal/cm 3 ) ^1/2 .

Using the adhesive (Y-1) instead of the adhesive (X-1), a shear tensile test piece described later was prepared, and the oil surface adhesiveness was evaluated.

[Comparative Example 2]

100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 2 parts by mass of hexamethyl phosphate triamide as an organophosphorus compound were mixed and the adhesive was mixed to form an adhesive (Y-2) was prepared The SP value of the obtained adhesive (Y-2) was 10.9 (cal/cm 3 ) ^1/2 .

Using the adhesive (Y-2) instead of the adhesive (X-1), a shear tensile test piece described later was prepared, and the oil surface adhesiveness was evaluated.

[Comparative Example 3]

100 parts by mass of bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 3 parts by mass of phenol novolac resin as an epoxy resin curing agent, and 1 part by mass of EPDM as an elastomer are mixed to form an adhesive (Y- 3) was prepared. The SP value of the obtained adhesive (Y-3) was 10.8 (cal/cm 3 ) ^1/2 .

Using the adhesive (Y-3) instead of the adhesive (X-1), a shear tensile test piece described later was produced, and the oil surface adhesiveness was evaluated. In addition, the average tensile elastic modulus at room temperature of the bonding part was 1200 MPa, and the average tensile elastic modulus at 150 degreeC was 800 MPa.

[Comparative Example 4]

80 parts by mass of isobutyl methacrylate and 20 parts by mass of polymethyl methacrylate were mixed to prepare an adhesive (Y-4). The SP value of the obtained adhesive (Y-4) was 7.5 (cal/cm 3 ) ^1/2 .

Using the adhesive (Y-4) instead of the adhesive (X-1), a shear tensile test piece to be described later was produced, and the oil surface adhesiveness was evaluated.

[Comparative Example 5]

100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 3 parts by mass of a phenol novolac resin as an epoxy resin curing agent, and 5 parts by mass of cyclohexanol as a solvent. An adhesive (Y-5) was prepared. The SP value of the obtained adhesive (Y-5) was 11.0 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1 except that the adhesive (Y-5) was used instead of the adhesive (X-1).

[Comparative Example 6]

An adhesive (Y-6) was prepared by mixing 100 parts by mass of an acrylic modified epoxy resin in which the acrylic resin was graft-polymerized (content of acrylic resin: 85% by mass) and 20 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (Y-6) was 7.0 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (Y-6) was used instead of the adhesive (X-1).

[Comparative Example 7]

100 parts by mass of an acrylic-modified epoxy resin in which the acrylic resin is graft-polymerized (content of acrylic resin: 75% by mass), 20 parts by mass of a phenol novolac resin as an epoxy resin curing agent, and 60 parts by mass of ethylene propylene diene rubber (EPDM) as an elastomer The parts were mixed to prepare an adhesive (Y-7). The SP value of the obtained adhesive (Y-7) was 7.4 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1 except that the adhesive (Y-7) was used instead of the adhesive (X-1).

[Comparative Example 8]

An adhesive (Y-8) was prepared by mixing 100 parts by mass of a bisphenol A epoxy resin (Tg: 105° C.) obtained by polymerizing bisphenol A and epichlorohydrin and 3 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (Y-8) was 10.8 (cal/cm 3 ) ^1/2 .

Oil surface adhesion, vibration and noise were evaluated in the same manner as in Example 1, except that the adhesive (Y-8) was used instead of the adhesive (X-1).

[Comparative Example 9]

An adhesive (Y-9) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 40 parts by mass of a phenol novolac resin as an epoxy resin curing agent. The SP value of the obtained adhesive (Y-9) was 7.5 (cal/cm 3 ) ^1/2 .

Oil surface adhesion, vibration and noise were evaluated in the same manner as in Example 1, except that the adhesive (Y-9) was used instead of the adhesive (X-1).

[Comparative Example 10]

An adhesive (Y-10) was prepared by mixing 100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F and 40 parts by mass of hexamethyl phosphate triamide as an organophosphorus compound. . The SP value of the obtained adhesive (Y-10) was 7.7 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (Y-10) was used instead of the adhesive (X-1).

[Comparative Example 11]

100 parts by mass of a bisphenol F-type epoxy resin (Tg: 130° C.) obtained by polymerizing epichlorohydrin and bisphenol F, 20 parts by mass of phenol novolac resin as an epoxy resin curing agent, and 60 parts by mass of EPDM as an elastomer. Y-11) was prepared. The SP value of the obtained adhesive (Y-11) was 7.6 (cal/cm 3 ) ^1/2 .

Oil surface adhesiveness, vibration, and noise were evaluated in the same manner as in Example 1, except that the adhesive (Y-11) was used instead of the adhesive (X-1).

[Evaluation of oil surface adhesion]

According to JIS K6850:1999, the oil surface adhesiveness produced a shear tensile test piece, measured adhesive strength, and evaluated the following evaluation criteria.

Si: 3.0 mass %, Al: 0.5 mass %, Mn: 0.1 mass % from a steel sheet 0.3 mm thick having a composition for non-oriented electrical steel sheet containing two rectangular steel sheets for testing (width 25 mm x length 100 mm) cut out Mineral oil as punching oil (SP value: 8.5 (cal/cm 3 ) ^1/2 ) was applied to the entire single side of each steel sheet for testing so that the application amount was 50 mg/m 2 . On the oil level of one test steel sheet, the adhesive is applied to a portion from the tip to 10 mm in an amount of 1 g/m2, and the other test steel sheet is applied to the oil level so that the portions up to 10 mm from the tip are in contact with each other. They overlapped so that they faced each other. They were thermocompression-bonded under the conditions of a temperature of 100 degreeC and a pressure of 100 Pa, and the shear tension test piece was obtained.

The tensile test environment was made into room temperature (25 degreeC). The test speed was 3 mm/min. A result is shown in Table 2.

(Evaluation standard)

A: The peeling strength is 250 kgf/cm<2> or more.

B: Peel strength is 200 kgf/cm 2 or more and less than 250 kgf/cm 2 .

C: The peel strength is 150 kgf/cm<2> or more and less than 200 kgf/cm<2>.

D: Peel strength is 100 kgf/cm 2 or more and less than 150 kgf/cm 2 .

E: Peel strength is 70 kgf/cm<2> or more and less than 100 kgf/cm<2>.

F: Peel strength is 50 kgf/cm 2 or more and less than 70 kgf/cm 2 .

G: Peel strength is 10 kgf/cm 2 or more and less than 50 kgf/cm 2 .

H: Peel strength is less than 10 kgf/cm 2 .

[Noise Vibration Evaluation]

(Production of test stator core)

A hoop having a composition for a non-oriented electrical steel sheet containing Si: 3.0 mass%, Al: 0.5 mass%, and Mn: 0.1 mass% was produced. The thickness of the steel was 0.3 mm. An insulating coating liquid containing a metal phosphate salt and an acrylic resin emulsion was applied to this hoop, and the mixture was baked at 300°C to give an insulating coating of a predetermined amount.

This hoop (electromagnetic steel sheet) was formed in a ring shape with an outer diameter of 300 mm and an inner diameter of 240 mm by the following procedure using the manufacturing apparatus 100 having the configuration shown in Fig. 4, and has a length of 30 mm and a width of 15 on the inner diameter side. A stator core was produced by punching out and sequentially stacking a single plate core provided with 18 mm rectangular teeth.

The hoops were sequentially sent out from the coil C in the direction of the arrow F in FIG. 4 . And with respect to this hoop, the punching process by the punching station 110 was performed first, and, then, the punching process by the punching station 120 was performed with respect to this hoop. By these punching processes, the shape of the electrical steel sheet 40 which has the core back part 22 and the some tooth part 23 shown in FIG. 3 was formed in the hoop (punching process).

Subsequently, the adhesive of each example is applied by the applicator 131 at the adhesive application station 130, as shown in FIG. 3, the lower surface (first surface) of the tooth part 23 and the core back part 22 of the hoop. was applied in a dotted shape (application step). The average diameter of the bonding portion in the tooth portion 23 was 5 mm, and the average diameter of the bonding portion in the core back portion 22 was 7 mm.

Subsequently, the hoops sent out to the lamination station 150 were punched and pressed into a single plate core with the outer periphery punching male die 154 (lamination process). Moreover, at this time, it heated to 80 degreeC with the heating device 151, and hardening of the adhesive agent was accelerated|stimulated.

The above punching process, application process, and lamination process were sequentially repeated, and the stator core for a test which laminated|stacked 130 single plate cores was obtained.

(Percussion test (noise vibration evaluation))

The outer peripheral end of the core bag part of the produced test stator core is excited in the radial direction with an impact hammer, and the tip of the tooth part in the direction of 180° in the axial direction with respect to the excitation circle and the center part of the core back part are used as measurement points, Modal analysis of noise and vibration was performed. In addition, even when the radial central part of the core back part is excited in the axial direction with an impact hammer, the tip of the tooth part and the center part of the core back part in the direction of 180° in the axial direction with respect to the excitation circle are the measurement points. , a modal analysis of noise and vibration was performed. Evaluation was performed according to the following criteria. It means that noise and vibration can be suppressed so that the numerical value is small.

1: Only one or two vibration peaks are detected.

2: Several vibration peaks are detected.

3: Ten or more vibration peaks are detected depending on the excitation direction.

4: Although there is a main peak, 10 or more vibration peaks are detected.

5: There is no main peak, and 10 or more vibration peaks are detected.

ADVANTAGE OF THE INVENTION According to this invention, the adhesive strength of the electrical steel sheets after punching in a laminated core can be improved. Therefore, the industrial applicability is great.

10: rotating electric machine
20: stator
21: adhesive laminated core for stator
40: electronic steel plate
41: adhesive part

Claims (14)

a plurality of electrical steel sheets laminated on each other, both surfaces of which are coated with an insulating film;
an adhesive portion disposed between the electrical steel sheets adjacent in the lamination direction and bonding these electrical steel sheets to each other;
all the sets of the electrical steel sheets adjacent in the lamination direction are adhered to each other by the plurality of bonding portions between the electrical steel sheets;
The bonding portion is provided at a plurality of places between the electrical steel sheets,
The laminated core, wherein the bonding portion is formed of an adhesive containing either or both of an acrylic resin and an epoxy resin, and having an SP value of 7.8 to 10.7 (cal/cm 3 ) ^1/2. The laminated core according to claim 1, wherein the adhesive is an epoxy resin-based adhesive containing an epoxy resin and a phenol novolac resin. The laminated core according to claim 2, wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an epoxy resin and 5 to 35 parts by mass of a phenol novolac resin. The laminated core according to claim 2, wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an epoxy resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 50 parts by mass of an elastomer. The epoxy resin adhesive according to claim 2, wherein the epoxy resin adhesive is 100 parts by mass of an epoxy resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 35 mass of a solvent ^{having an SP value of 7.0 to 10.7 (cal/cm 3 ) 1/2.} A laminated core, which is an adhesive consisting of parts. The laminated core according to claim 2, wherein the epoxy resin-based adhesive further contains an acrylic resin. The laminated core according to claim 6, wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an acrylic modified epoxy resin obtained by graft polymerization of an acrylic resin and 5 to 35 parts by mass of a phenol novolac resin. The laminate according to claim 6, wherein the epoxy resin adhesive is an adhesive comprising 100 parts by mass of an acrylic modified epoxy resin obtained by graft polymerization of an acrylic resin, 5 to 35 parts by mass of a phenol novolak resin, and 5 to 50 parts by mass of an elastomer. core. The laminated core according to claim 1, wherein the adhesive is an epoxy resin adhesive containing an epoxy resin having a glass transition temperature of 120 to 180°C and an organophosphorus compound. The laminated core according to claim 1, wherein the adhesive is an epoxy resin adhesive comprising 100 parts by mass of an epoxy resin and 5 to 35 parts by mass of an organophosphorus compound. The method according to claim 1, wherein the adhesive is an epoxy resin-based adhesive comprising an epoxy resin, an epoxy resin curing agent, and an elastomer,
An average tensile modulus of elasticity at room temperature of the bonding portion is 1500 to 5000 MPa, and an average tensile modulus of elasticity at 150°C is 1000 to 3000 MPa, the laminated core. The laminate core according to any one of claims 1 to 11, which is an adhesive laminate core for a stator. A rotating electric machine comprising the laminated core according to any one of claims 1 to 12. A method for producing the laminated core according to claim 1,
A method for manufacturing a laminated core, wherein the adhesive is applied to the surface of the electrical steel sheet and then overlapped and pressed on a separate electrical steel sheet to repeat the operation of forming the bonding portion.

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